Example (cont.)
Recalculate the plasma jet example by assuming the diameter of the particles is 1 mm. (a) Determine the time for the center temperature to reach the melting point, (b) Total time to melt the entire particle. First, use the lumped capacitance method and then compare the results to that determined using Heisler charts. (h=30000 W/m2, k=10.5 W/m.K, ?r=3970 kg/m3, rO=0.5 mm, cP=1560 J/kg.K, T?=10000 K, Ti=300 K, Tmelt=2318 , hsf=3577 kJ/kg, a=k/(rcP)=1.695?10-6(m2/s).
First, Bi=(h/k)(rO/3)=0.476ɬ.1 should not use LCM. However, we will use it anyway to compare the difference.